The invention is based on a quantity control valve for a fuel injection system used in internal combustion engine.
From German Patent Application DE 195 49 108.4, which had not been published by the filing date of the present priority application, among other things a quantity control valve is disclosed, which has a longitudinal slide that is movable in a valve housing between:a restoring spring chamber and a control chamber and that opens counter to the action of a restoring spring. The hollow longitudinal slide is acted upon by fuel from a low-pressure pump via the restoring spring chamber. By means of a throttle restriction located in the longitudinal slide, the fuel reaches the control chamber. As soon as the fuel pressure there exceeds a certain value, the longitudinal slide opens counter to the action of the relief chamber, and as a result, the fuel reaches the high-pressure pump through the longitudinal slide, via an outlet bore that has been opened. The opening of the valve is additionally reinforced with the aid of an electromagnetic drive acting directly on the longitudinal slide.
A quantity control valve is also known from European Patent Disclosure EP 0 299 337; it has a pressure slide for controlling the flow cross section to the high-pressure pump. Such a valve cannot be controlled precisely enough and requires a complicated lever arrangement for its actuation.